Huntington’s disease is an autosomal dominant condition characterized by choreatic movements, psychiatric disturbances and dementia.
It disease is caused by an increased number of CAG trinucleotide repeats (36 or more) on the short arm of chromosome 4.
Classical symptoms and signs are:
- Chorea
- Depression
- Irritability
- Depression
Onset tends to be between the ages of 30 and 50. More CAG repeats = earlier onset. Due to anticipation it also presents earlier in successive generations of families. The average period between onset of symptoms and death is 17 years.
There is no cure. The chorea may be treated with a dopamine antagonist such as tetrabenazine.
Small print gem: CAG is the codon for the amino acid glutamic.
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